diff --git a/ports/unix/coverage.c b/ports/unix/coverage.c
index f545674ceeb80..64701e4e7000c 100644
--- a/ports/unix/coverage.c
+++ b/ports/unix/coverage.c
@@ -552,7 +552,9 @@ STATIC mp_obj_t extra_coverage(void) {
         code_state->exc_sp_idx = 0;
         code_state->old_globals = NULL;
         mp_vm_return_kind_t ret = mp_execute_bytecode(code_state, MP_OBJ_NULL);
-        mp_printf(&mp_plat_print, "%d %d\n", ret, mp_obj_get_type(code_state->state[0]) == &mp_type_NotImplementedError);
+        mp_printf(&mp_plat_print, "%d %d\n",
+            ret == MP_VM_RETURN_EXCEPTION,
+            mp_obj_get_type(code_state->state[0]) == &mp_type_NotImplementedError);
     }
 
     // scheduler
diff --git a/py/compile.c b/py/compile.c
index 76d4c1bf5aa0a..5d384a4fb9828 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -938,7 +938,7 @@ STATIC void compile_decorated(compiler_t *comp, mp_parse_node_struct_t *pns) {
         mp_parse_node_struct_t *pns0 = (mp_parse_node_struct_t *)pns_body->nodes[0];
         body_name = compile_funcdef_helper(comp, pns0, emit_options);
         scope_t *fscope = (scope_t *)pns0->nodes[4];
-        fscope->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
+        fscope->scope_flags |= MP_SCOPE_FLAG_GENERATOR | MP_SCOPE_FLAG_ASYNCDEF;
     #endif
     } else {
         assert(MP_PARSE_NODE_STRUCT_KIND(pns_body) == PN_classdef); // should be
@@ -1041,6 +1041,12 @@ STATIC void compile_return_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
         return;
     }
     #endif
+    #if MICROPY_PY_ASYNC_AWAIT
+    if ((comp->scope_cur->scope_flags & MP_SCOPE_FLAG_ASYNCGENERATOR)
+        && !MP_PARSE_NODE_IS_NULL(pns->nodes[0])) {
+        compile_syntax_error(comp, (mp_parse_node_t)pns, MP_ERROR_TEXT("'return' with value in async generator"));
+    }
+    #endif
     if (MP_PARSE_NODE_IS_NULL(pns->nodes[0])) {
         // no argument to 'return', so return None
         EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
@@ -1765,6 +1771,7 @@ STATIC void compile_with_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
 }
 
 STATIC void compile_yield_from(compiler_t *comp) {
+    comp->scope_cur->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
     EMIT_ARG(get_iter, false);
     EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
     EMIT_ARG(yield, MP_EMIT_YIELD_FROM);
@@ -1959,7 +1966,7 @@ STATIC void compile_async_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
         // async def
         compile_funcdef(comp, pns0);
         scope_t *fscope = (scope_t *)pns0->nodes[4];
-        fscope->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
+        fscope->scope_flags |= MP_SCOPE_FLAG_GENERATOR | MP_SCOPE_FLAG_ASYNCDEF;
     } else {
         // async for/with; first verify the scope is a generator
         int scope_flags = comp->scope_cur->scope_flags;
@@ -2711,6 +2718,12 @@ STATIC void compile_yield_expr(compiler_t *comp, mp_parse_node_struct_t *pns) {
         compile_syntax_error(comp, (mp_parse_node_t)pns, MP_ERROR_TEXT("'yield' outside function"));
         return;
     }
+    comp->scope_cur->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
+    #if MICROPY_PY_ASYNC_AWAIT
+    if (comp->scope_cur->scope_flags & MP_SCOPE_FLAG_ASYNCDEF) {
+        comp->scope_cur->scope_flags |= MP_SCOPE_FLAG_ASYNCGENERATOR;
+    }
+    #endif
     if (MP_PARSE_NODE_IS_NULL(pns->nodes[0])) {
         EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
         EMIT_ARG(yield, MP_EMIT_YIELD_VALUE);
@@ -2719,6 +2732,11 @@ STATIC void compile_yield_expr(compiler_t *comp, mp_parse_node_struct_t *pns) {
         pns = (mp_parse_node_struct_t *)pns->nodes[0];
         compile_node(comp, pns->nodes[0]);
         compile_yield_from(comp);
+        #if MICROPY_PY_ASYNC_AWAIT
+        if (comp->scope_cur->scope_flags & MP_SCOPE_FLAG_ASYNCDEF) {
+            compile_syntax_error(comp, (mp_parse_node_t)pns, MP_ERROR_TEXT("'yield from' in async function"));
+        }
+        #endif
     } else {
         compile_node(comp, pns->nodes[0]);
         EMIT_ARG(yield, MP_EMIT_YIELD_VALUE);
@@ -2920,6 +2938,7 @@ STATIC void compile_scope_comp_iter(compiler_t *comp, mp_parse_node_struct_t *pn
         // no more nested if/for; compile inner expression
         compile_node(comp, pn_inner_expr);
         if (comp->scope_cur->kind == SCOPE_GEN_EXPR) {
+            comp->scope_cur->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
             EMIT_ARG(yield, MP_EMIT_YIELD_VALUE);
             reserve_labels_for_native(comp, 1);
             EMIT(pop_top);
diff --git a/py/emitbc.c b/py/emitbc.c
index 70a4d8b12e18a..374feb2e93a12 100644
--- a/py/emitbc.c
+++ b/py/emitbc.c
@@ -800,7 +800,6 @@ void mp_emit_bc_raise_varargs(emit_t *emit, mp_uint_t n_args) {
 void mp_emit_bc_yield(emit_t *emit, int kind) {
     MP_STATIC_ASSERT(MP_BC_YIELD_VALUE + 1 == MP_BC_YIELD_FROM);
     emit_write_bytecode_byte(emit, -kind, MP_BC_YIELD_VALUE + kind);
-    emit->scope->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
 }
 
 void mp_emit_bc_start_except_handler(emit_t *emit) {
diff --git a/py/emitnative.c b/py/emitnative.c
index 2d694983bd2ab..48e4e73a1b44b 100644
--- a/py/emitnative.c
+++ b/py/emitnative.c
@@ -2831,7 +2831,6 @@ STATIC void emit_native_yield(emit_t *emit, int kind) {
     if (emit->do_viper_types) {
         mp_raise_NotImplementedError(MP_ERROR_TEXT("native yield"));
     }
-    emit->scope->scope_flags |= MP_SCOPE_FLAG_GENERATOR;
 
     need_stack_settled(emit);
 
@@ -2853,7 +2852,13 @@ STATIC void emit_native_yield(emit_t *emit, int kind) {
     emit_native_mov_state_reg(emit, OFFSETOF_CODE_STATE_SP, REG_TEMP0);
 
     // Put return type in return value slot
-    ASM_MOV_REG_IMM(emit->as, REG_TEMP0, MP_VM_RETURN_YIELD);
+    mp_vm_return_kind_t ret_kind = MP_VM_RETURN_YIELD;
+    #if MICROPY_PY_ASYNC_AWAIT
+    if ((emit->scope->scope_flags & MP_SCOPE_FLAG_ASYNCGENERATOR) && kind == MP_EMIT_YIELD_FROM) {
+        ret_kind = MP_VM_RETURN_YIELD_FROM;
+    }
+    #endif
+    ASM_MOV_REG_IMM(emit->as, REG_TEMP0, ret_kind);
     ASM_MOV_LOCAL_REG(emit->as, LOCAL_IDX_RET_VAL(emit), REG_TEMP0);
 
     // Save re-entry PC
diff --git a/py/obj.h b/py/obj.h
index b5b855bad395c..3b6408ce7df22 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -813,6 +813,7 @@ extern const mp_obj_type_t mp_type_super;
 extern const mp_obj_type_t mp_type_gen_wrap;
 extern const mp_obj_type_t mp_type_native_gen_wrap;
 extern const mp_obj_type_t mp_type_gen_instance;
+extern const mp_obj_type_t mp_type_agen_instance;
 extern const mp_obj_type_t mp_type_fun_builtin_0;
 extern const mp_obj_type_t mp_type_fun_builtin_1;
 extern const mp_obj_type_t mp_type_fun_builtin_2;
diff --git a/py/objgenerator.c b/py/objgenerator.c
index 8175dbd683db0..c9639143ddf82 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2013-2019 Damien P. George
+ * Copyright (c) 2013-2020 Damien P. George
  * Copyright (c) 2014-2017 Paul Sokolovsky
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -29,6 +29,7 @@
 #include <assert.h>
 
 #include "py/runtime.h"
+#include "py/bc0.h"
 #include "py/bc.h"
 #include "py/objstr.h"
 #include "py/objgenerator.h"
@@ -63,6 +64,12 @@ STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, size_t n_args, size_t n_kw, cons
         n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t),
         &mp_type_gen_instance);
 
+    #if MICROPY_PY_ASYNC_AWAIT
+    if (scope_flags & MP_SCOPE_FLAG_ASYNCGENERATOR) {
+        o->base.type = &mp_type_agen_instance;
+    }
+    #endif
+
     o->pend_exc = mp_const_none;
     o->code_state.fun_bc = self_fun;
     o->code_state.n_state = n_state;
@@ -116,6 +123,11 @@ STATIC mp_obj_t native_gen_wrap_call(mp_obj_t self_in, size_t n_args, size_t n_k
 
     // Allocate the generator object, with room for local stack (exception stack not needed).
     mp_obj_gen_instance_native_t *o = mp_obj_malloc_var(mp_obj_gen_instance_native_t, byte, n_state * sizeof(mp_obj_t), &mp_type_gen_instance);
+    #if MICROPY_PY_ASYNC_AWAIT
+    if (scope_flags & MP_SCOPE_FLAG_ASYNCGENERATOR) {
+        o->base.type = &mp_type_agen_instance;
+    }
+    #endif
 
     // Parse the input arguments and set up the code state
     o->pend_exc = mp_const_none;
@@ -167,6 +179,13 @@ mp_vm_return_kind_t mp_obj_gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_
     mp_obj_gen_instance_t *self = MP_OBJ_TO_PTR(self_in);
     if (self->code_state.ip == 0) {
         // Trying to resume an already stopped generator.
+        #if MICROPY_PY_ASYNC_AWAIT
+        if (self->base.type == &mp_type_agen_instance) {
+            // Do a "raise StopAsyncIteration()".
+            *ret_val = mp_obj_new_exception(&mp_type_StopAsyncIteration);
+            return MP_VM_RETURN_EXCEPTION;
+        }
+        #endif
         // This is an optimised "raise StopIteration(None)".
         *ret_val = mp_const_none;
         return MP_VM_RETURN_NORMAL;
@@ -235,13 +254,42 @@ mp_vm_return_kind_t mp_obj_gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_
             self->code_state.ip = 0;
             // This is an optimised "raise StopIteration(*ret_val)".
             *ret_val = *self->code_state.sp;
+            #if MICROPY_PY_ASYNC_AWAIT
+            if (self->base.type == &mp_type_agen_instance) {
+                // Reached the end of the async generator, do "raise StopAsyncIteration()".
+                assert(*ret_val == mp_const_none); // enforced by the compiler
+                *ret_val = mp_obj_new_exception(&mp_type_StopAsyncIteration);
+                ret_kind = MP_VM_RETURN_EXCEPTION;
+            }
+            #endif
             break;
 
         case MP_VM_RETURN_YIELD:
+        case MP_VM_RETURN_YIELD_FROM:
             *ret_val = *self->code_state.sp;
             #if MICROPY_PY_GENERATOR_PEND_THROW
             *self->code_state.sp = mp_const_none;
             #endif
+            #if MICROPY_PY_ASYNC_AWAIT
+            if (self->base.type == &mp_type_agen_instance) {
+                #if MICROPY_EMIT_NATIVE
+                if (self->code_state.exc_sp_idx == MP_CODE_STATE_EXC_SP_IDX_SENTINEL) {
+                    // A native generator.
+                    if (ret_kind == MP_VM_RETURN_YIELD) {
+                        // "yield" in native async generator.
+                        ret_kind = MP_VM_RETURN_NORMAL;
+                    } else {
+                        // "yield from" in native async generator.
+                        ret_kind = MP_VM_RETURN_YIELD;
+                    }
+                } else
+                #endif
+                if (*self->code_state.ip != MP_BC_YIELD_FROM) {
+                    // "yield" in async generator.
+                    ret_kind = MP_VM_RETURN_NORMAL;
+                }
+            }
+            #endif
             break;
 
         case MP_VM_RETURN_EXCEPTION: {
@@ -374,3 +422,25 @@ MP_DEFINE_CONST_OBJ_TYPE(
     iter, gen_instance_iternext,
     locals_dict, &gen_instance_locals_dict
     );
+
+/******************************************************************************/
+// async generator instance
+
+#if MICROPY_PY_ASYNC_AWAIT
+
+STATIC const mp_rom_map_elem_t agen_instance_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___aiter__), MP_ROM_PTR(&mp_identity_obj) },
+    { MP_ROM_QSTR(MP_QSTR___anext__), MP_ROM_PTR(&mp_identity_obj) },
+};
+STATIC MP_DEFINE_CONST_DICT(agen_instance_locals_dict, agen_instance_locals_dict_table);
+
+MP_DEFINE_CONST_OBJ_TYPE(
+    mp_type_agen_instance,
+    MP_QSTR_async_generator,
+    MP_TYPE_FLAG_ITER_IS_ITERNEXT,
+    unary_op, mp_generic_unary_op,
+    iter, gen_instance_iternext,
+    locals_dict, &agen_instance_locals_dict
+    );
+
+#endif // MICROPY_PY_ASYNC_AWAIT
diff --git a/py/runtime.c b/py/runtime.c
index 23fae6041dd0f..3e1f3986be8c1 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -1387,7 +1387,11 @@ mp_vm_return_kind_t mp_resume(mp_obj_t self_in, mp_obj_t send_value, mp_obj_t th
     assert((send_value != MP_OBJ_NULL) ^ (throw_value != MP_OBJ_NULL));
     const mp_obj_type_t *type = mp_obj_get_type(self_in);
 
-    if (type == &mp_type_gen_instance) {
+    if (type == &mp_type_gen_instance
+        #if MICROPY_PY_ASYNC_AWAIT
+        || type == &mp_type_agen_instance
+        #endif
+        ) {
         return mp_obj_gen_resume(self_in, send_value, throw_value, ret_val);
     }
 
diff --git a/py/runtime.h b/py/runtime.h
index 36b3caa6c73e6..965051a68b177 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -32,6 +32,7 @@
 typedef enum {
     MP_VM_RETURN_NORMAL,
     MP_VM_RETURN_YIELD,
+    MP_VM_RETURN_YIELD_FROM, // used only by the native emitter
     MP_VM_RETURN_EXCEPTION,
 } mp_vm_return_kind_t;
 
diff --git a/py/runtime0.h b/py/runtime0.h
index c82a4717f4516..88e792ecbee2b 100644
--- a/py/runtime0.h
+++ b/py/runtime0.h
@@ -26,19 +26,23 @@
 #ifndef MICROPY_INCLUDED_PY_RUNTIME0_H
 #define MICROPY_INCLUDED_PY_RUNTIME0_H
 
-// The first four must fit in 8 bits, see emitbc.c
-// The remaining must fit in 16 bits, see scope.h
-#define MP_SCOPE_FLAG_ALL_SIG      (0x0f)
+// The first five must fit in 7 bits, see mp_raw_code_t.scope_flags.
+// The remaining must fit in 16 bits, see scope_t.scope_flags.
+#define MP_SCOPE_FLAG_ALL_SIG      (0x1f)
+
 #define MP_SCOPE_FLAG_GENERATOR    (0x01)
 #define MP_SCOPE_FLAG_VARKEYWORDS  (0x02)
 #define MP_SCOPE_FLAG_VARARGS      (0x04)
 #define MP_SCOPE_FLAG_DEFKWARGS    (0x08)
-#define MP_SCOPE_FLAG_REFGLOBALS   (0x10) // used only if native emitter enabled
-#define MP_SCOPE_FLAG_HASCONSTS    (0x20) // used only if native emitter enabled
-#define MP_SCOPE_FLAG_VIPERRET_POS    (6) // 3 bits used for viper return type, to pass from compiler to native emitter
-#define MP_SCOPE_FLAG_VIPERRELOC   (0x10) // used only when loading viper from .mpy
-#define MP_SCOPE_FLAG_VIPERRODATA  (0x20) // used only when loading viper from .mpy
-#define MP_SCOPE_FLAG_VIPERBSS     (0x40) // used only when loading viper from .mpy
+#define MP_SCOPE_FLAG_ASYNCGENERATOR (0x10)
+
+#define MP_SCOPE_FLAG_REFGLOBALS   (0x20) // used only if native emitter enabled
+#define MP_SCOPE_FLAG_HASCONSTS    (0x40) // used only if native emitter enabled
+#define MP_SCOPE_FLAG_VIPERRET_POS    (7) // 3 bits used for viper return type, to pass from compiler to native emitter
+#define MP_SCOPE_FLAG_VIPERRELOC   (0x20) // used only when loading viper from .mpy
+#define MP_SCOPE_FLAG_VIPERRODATA  (0x40) // used only when loading viper from .mpy
+#define MP_SCOPE_FLAG_VIPERBSS     (0x80) // used only when loading viper from .mpy
+#define MP_SCOPE_FLAG_ASYNCDEF     (0x8000) // used ony by the compiler
 
 // types for native (viper) function signature
 #define MP_NATIVE_TYPE_OBJ  (0x00)
diff --git a/tests/basics/async_agen.py b/tests/basics/async_agen.py
new file mode 100644
index 0000000000000..7e0d1e0efdcb4
--- /dev/null
+++ b/tests/basics/async_agen.py
@@ -0,0 +1,79 @@
+# Test async generators
+
+# helper
+def run_task(t):
+    while True:
+        try:
+            t.send(None)
+        except Exception as er:
+            print('run_task finished with', repr(er))
+            break
+
+# Test SyntaxError
+
+try:
+    exec('async def f(): yield from y')
+except Exception as er:
+    print(type(er))
+
+try:
+    exec('async def f(): yield; return 1')
+except Exception as er:
+    print(type(er))
+
+try:
+    exec('async def f(): return 2; yield')
+except Exception as er:
+    print(type(er))
+
+# Test core behaviour
+
+async def genfunc():
+    yield 1
+    yield 2
+
+async def main():
+    gen = genfunc()
+
+    print(gen.__aiter__() is gen)
+
+    print(repr(await gen.__anext__())) # should be 1
+    print(repr(await gen.__anext__())) # should be 2
+
+    try:
+        await gen.__anext__()
+    except Exception as er:
+        print(type(er))
+
+    try:
+        await gen.__anext__()
+    except Exception as er:
+        print(type(er))
+
+run_task(main())
+
+# Test async-for iterating over an async generator
+
+class Wait:
+    def __init__(self, n):
+        self.n = n
+    def __await__(self):
+        return self
+    __iter__ = __await__ # needed for uPy
+    def __next__(self):
+        if self.n == 0:
+            raise StopIteration
+        print('wait', self.n)
+        self.n -= 1
+
+async def gen():
+    for i in range(4):
+        yield i
+        await Wait(2)
+
+async def main():
+    g = gen()
+    async for a in g:
+        print('got', a)
+
+run_task(main())
diff --git a/tests/basics/async_agen.py.exp b/tests/basics/async_agen.py.exp
new file mode 100644
index 0000000000000..acb0c0f598730
--- /dev/null
+++ b/tests/basics/async_agen.py.exp
@@ -0,0 +1,22 @@
+<class 'SyntaxError'>
+<class 'SyntaxError'>
+<class 'SyntaxError'>
+True
+1
+2
+<class 'StopAsyncIteration'>
+<class 'StopAsyncIteration'>
+run_task finished with StopIteration()
+got 0
+wait 2
+wait 1
+got 1
+wait 2
+wait 1
+got 2
+wait 2
+wait 1
+got 3
+wait 2
+wait 1
+run_task finished with StopIteration()
diff --git a/tests/micropython/import_mpy_native.py b/tests/micropython/import_mpy_native.py
index 73e20694cc27e..f83dac048d600 100644
--- a/tests/micropython/import_mpy_native.py
+++ b/tests/micropython/import_mpy_native.py
@@ -101,7 +101,7 @@ def open(self, path, mode):
 
             b'\x22' # 4 bytes, no children, viper code
                 b'\x00\x00\x00\x00' # dummy machine code
-                b'\x70' # scope_flags: VIPERBSS | VIPERRODATA | VIPERRELOC
+                b'\xe0' # scope_flags: VIPERBSS | VIPERRODATA | VIPERRELOC
                 b'\x06\x04' # rodata=6 bytes, bss=4 bytes
                 b'rodata' # rodata content
                 b'\x03\x01\x00' # dummy relocation of rodata
diff --git a/tests/micropython/import_mpy_native_gc.py b/tests/micropython/import_mpy_native_gc.py
index e18720fb31473..247665f530ce3 100644
--- a/tests/micropython/import_mpy_native_gc.py
+++ b/tests/micropython/import_mpy_native_gc.py
@@ -49,9 +49,9 @@ def open(self, path, mode):
 # by the required value of sys.implementation._mpy (without sub-version).
 features0_file_contents = {
     # -march=x64
-    0x806: b'M\x06\x09\x1f\x02\x004build/features0.native.mpy\x00\x12factorial\x00\x8a\x02\xe9/\x00\x00\x00SH\x8b\x1d\x83\x00\x00\x00\xbe\x02\x00\x00\x00\xffS\x18\xbf\x01\x00\x00\x00H\x85\xc0u\x0cH\x8bC \xbe\x02\x00\x00\x00[\xff\xe0H\x0f\xaf\xf8H\xff\xc8\xeb\xe6ATUSH\x8b\x1dQ\x00\x00\x00H\x8bG\x08L\x8bc(H\x8bx\x08A\xff\xd4H\x8d5+\x00\x00\x00H\x89\xc5H\x8b\x059\x00\x00\x00\x0f\xb7x\x02\xffShH\x89\xefA\xff\xd4H\x8b\x03[]A\\\xc3\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x11$\r&\xa3 \x01"\xff',
+    0x806: b'M\x06\t\x1f\x02\x004build/features0.native.mpy\x00\x12factorial\x00\x8a\x02\xe9/\x00\x00\x00SH\x8b\x1d\x83\x00\x00\x00\xbe\x02\x00\x00\x00\xffS\x18\xbf\x01\x00\x00\x00H\x85\xc0u\x0cH\x8bC \xbe\x02\x00\x00\x00[\xff\xe0H\x0f\xaf\xf8H\xff\xc8\xeb\xe6ATUSH\x8b\x1dQ\x00\x00\x00H\x8bG\x08L\x8bc(H\x8bx\x08A\xff\xd4H\x8d5+\x00\x00\x00H\x89\xc5H\x8b\x059\x00\x00\x00\x0f\xb7x\x02\xffShH\x89\xefA\xff\xd4H\x8b\x03[]A\\\xc3\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 \x11$\r&\xa3 \x01"\xff',
     # -march=armv6m
-    0x1006: b"M\x06\x11\x1f\x02\x004build/features0.native.mpy\x00\x12factorial\x00\x88\x02\x18\xe0\x00\x00\x10\xb5\tK\tJ{D\x9cX\x02!\xe3h\x98G\x03\x00\x01 \x00+\x02\xd0XC\x01;\xfa\xe7\x02!#i\x98G\x10\xbd\xc0Fj\x00\x00\x00\x00\x00\x00\x00\xf8\xb5\nN\nK~D\xf4XChgiXh\xb8G\x05\x00\x07K\x08I\xf3XyDX\x88ck\x98G(\x00\xb8G h\xf8\xbd\xc0F:\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x1e\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x11<\r>\xa38\x01:\xff",
+    0x1006: b"M\x06\x11\x1f\x02\x004build/features0.native.mpy\x00\x12factorial\x00\x88\x02\x18\xe0\x00\x00\x10\xb5\tK\tJ{D\x9cX\x02!\xe3h\x98G\x03\x00\x01 \x00+\x02\xd0XC\x01;\xfa\xe7\x02!#i\x98G\x10\xbd\xc0Fj\x00\x00\x00\x00\x00\x00\x00\xf8\xb5\nN\nK~D\xf4XChgiXh\xb8G\x05\x00\x07K\x08I\xf3XyDX\x88ck\x98G(\x00\xb8G h\xf8\xbd\xc0F:\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x1e\x00\x00\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 \x11<\r>\xa38\x01:\xff",
 }
 
 # Populate armv7m-derived archs based on armv6m.
diff --git a/tests/unix/extra_coverage.py.exp b/tests/unix/extra_coverage.py.exp
index ab6d497723012..61a53b72f7b4a 100644
--- a/tests/unix/extra_coverage.py.exp
+++ b/tests/unix/extra_coverage.py.exp
@@ -104,7 +104,7 @@ Warning: test
 123
 456
 # VM
-2 1
+1 1
 # scheduler
 sched(0)=1
 sched(1)=1
diff --git a/tools/mpy_ld.py b/tools/mpy_ld.py
index 05e70709ad8a4..59a2da623e30b 100755
--- a/tools/mpy_ld.py
+++ b/tools/mpy_ld.py
@@ -48,9 +48,9 @@
 MP_NATIVE_ARCH_XTENSA = 9
 MP_NATIVE_ARCH_XTENSAWIN = 10
 MP_PERSISTENT_OBJ_STR = 5
-MP_SCOPE_FLAG_VIPERRELOC = 0x10
-MP_SCOPE_FLAG_VIPERRODATA = 0x20
-MP_SCOPE_FLAG_VIPERBSS = 0x40
+MP_SCOPE_FLAG_VIPERRELOC = 0x20
+MP_SCOPE_FLAG_VIPERRODATA = 0x40
+MP_SCOPE_FLAG_VIPERBSS = 0x80
 MP_SMALL_INT_BITS = 31
 
 # ELF constants